System Management Controller SMC Reset

The System Management Controller (SMC) is a chip on the logic board that controls all power functions for the Xserve. If the Xserve is experiencing any power issue, resetting the SMC may resolve it. The SMC controls several functions, including:

Telling the Xserve when to turn on, turn off, sleep, wake, idle, and so forth

Handling system resets from various commands

Controlling the fans

It is also recommended that the SMC be reset on any new logic board after it is installed as part of a repair.

Note that resetting the SMC does not reset the PRAM. Resetting the SMC will not resolve issues in which the Xserve is unresponsive—in these situations, restarting the Xserve will generally suffice. If the Xserve isn't responding, perform these steps one at a time, in the following order, until the issue has been resolved:

Force Quit (Option-Command-Escape)

Restart (Control-Command-Power)

Force Shut Down (press the power button for 10 seconds)

Resetting the SMC can resolve some Xserve issues such as not starting up, not displaying video, sleep issues, fan noise issues, and so forth. If the Xserve still exhibits these types of issues after you've restarted the Xserve, try resetting the SMC. There are two ways to reset the SMC on the Xserve.

To reset the SMC in the Xserve (Late 2006):

Shut Down the Xserve, either locally or using remote commands (or if the Xserve is not responding, hold the power button until it turns off).

Unplug the AC power cord.

Wait at least 15 seconds.

Plug the power cord back in, making sure the power button is not being pressed at the time.